Why do state legislators vote the way they do? Which influence is predominant: ideology, party, or public opinion? The implementation votes surrounding the Affordable Care Act (ACA) provides a unique setting to examine this question, as they make all three considerations highly salient. State roll call votes on ACA implementation were sometimes polarized and sometimes unexpectedly bipartisan. What accounts for the heterogeneity in individual legislator behavior on bills implementing the ACA at the state level? Using new data on legislator ideology and votes from 2011-2015, I show evidence that legislator ideology was by far the most important predictor of voting on implementation votes, far more so than legislator party or public opinion. Moreover, I show the influence of ideology is heterogenous by issue area and bill.

Using new data on roll-call voting of U.S. state legislators and public opinion in their districts, we explain how ideological polarization of voters within districts can lead to legislative polarization. So-called “moderate” districts that switch hands between parties are often internally polarized: the ideological distance between Democrats and Republicans within these districts is often greater than the distance between liberal cities and conservative rural districts. We present a theoretical model in which intra-district ideological polarization makes candidates uncertain about the ideological location of the median voter, thereby reducing their incentives to offer moderate policy positions. We then demonstrate that among districts with similar median voter ideologies, the difference in legislative behavior between Democratic and Republican state legislators is greater in more ideologically heterogeneous districts. Our findings suggest that accounting for the subtleties of political geography can help explain the coexistence of a polarized legislature and a moderate mass public.

Income inequality and political polarization have both increased dramatically in the United States over the last several decades. A small but growing literature has suggested that these two phenomena may be related and mutually reinforcing: income inequality leads to political polarization, and the gridlock induced by polarization reduces the ability of politicians to alleviate rising inequality. Scholars, however, have not credibly identified the causal relationships. Using newly available data on polarization in state legislatures and state-level income inequality, we extend previous analyses to the US state level. Employing a relatively underutilized instrumental variables identification strategy allows us to obtain the first credible causal estimates of the effect of inequality on polarization within states. We find that income inequality has a large, positive and statistically significant effect on political polarization. Economic inequality appears to cause state Democratic parties to become more liberal. Inequality, however, moves state legislatures to the right overall. Such findings suggest that the effect of income inequality impacts polarization by replacing moderate Democratic legislators with Republicans.

Since passage of the Patient Protection and Affordable Care Act, several attempts have been made to block its provisions in the states. Among these, ballot propositions challenging the individual mandate have occurred in five states, with four more scheduled for November 2012. We first provide state-level estimates of public opinion on the ACA since the beginning of 2010, and we show that, consistent with models of partisan resonance, polarization of public opinion is greatest near elections that politicize health care. We then use synthetic control methods to estimate the causal effects of the high-profile public campaigns surrounding these proposition elections, finding these effects to be conditioned by the broader political context of the campaign. In Ohio, where the campaign took place without simultaneous major candidate elections, we find effects on opinion of about seven percentage points. These effects are fairly short-lived, persisting a few months.

Abstract: Two problems hinder the ability of scholars to assess the quality of representation of state-level public opinion by elected representatives. First, the main tool measuring ideology in public opinion has historically been self-reported, but this is now well known to be severely plagued by measurement error. Second, and far more binding, we lack a common scale on which to place both constituents and representatives. While the literature has addressed a number of methods estimating a common space for politicians’ ideal points across political institutions, little work exists that incorporates citizens into this space. The unified methodology in this paper solves both problems in order to assess representation of constituents by their individual state legislators, the parties in the state legislatures, and the state legislature as a whole. Bridging is accomplished using policy preference questions from a state and congressional candidate survey administered since the early 1990s. I ask those questions in my own 2008 survey of over 4,200 citizen respondents, representative at the state and national levels. Thus, citizens and state legislators can be located on the same ideological scale. I employ multilevel regression with poststratification to model state-level public ideology and obtain aggregate opinion estimates for all 50 states and 1942 upper chamber state legislative districts. State legislators and chamber and party medians are responsive to public opinion, but they are very often incongruent to it. Democrats and Republicans diverge from district and state opinion, but in an asymmetric fashion, with Republicans considerably more distant.

Advocates of direct primaries argued that party nominees selected by voters should be more independent-minded than those hand-selected by party elites. We test this claim through a study of state legislative vacancy appointments, through which a small group of party activists is responsible for replacing legislators who have died or resigned. We compare the roll call voting behavior of two decades of legislators in Colorado and Illinois based on whether the legislators were directly nominated in primary elections or selected by party elites on a partisan vacancy committee. Results demonstrate that there is, in fact, little ideological difference between the two types of incumbents, suggesting that party elites are largely able to secure the nominations of their preferred candidates even under conditions of a direct primary.

Abstract: In earlier work, we created Congressional common space scores for multiple state legislatures using bridge actors who served in both institutions. Here, we employ simulations to explore the general issues involved in bridging institutions in data-sparse environments, where only a few bridge actors exist to allow inter-institutional comparisons. We find that only a few such bridges are necessary to improve ideal point estimates of rescaled legislative chambers.

The Causes and Consequences of Party Switching in American State Legislatures

Abstract: The influence of parties is a perennial topic for debate. Do parties affect their member’s revealed preferences, or do they merely reflect them? Attempts to isolate party effects are fraught with inference problems. Using the natural experiment afforded by legislators switching parties, previous studies such as Nokken 2000, 2004 measure preference shifts. Assuming personal preferences to be constant, these shifts are held to reflect party pressure. The problem is that, due to the focus on Congress, only a miniscule number of modern cases exist, and institutional variation is minimal. Consequently, inferences drawn are not as strong. We use a new, original data set of state legislator ideology in 50 states from 1993-2008, drawing from roll call votes and legislator surveys. These ideal point estimates are in common space for cross-state comparability. We find nearly 170 party switchers at the state level, dwarfing by nearly five times that for postwar Congresses. We analyze the degree of ideological change revealed by party switchers, as well as their incidence.

Presidential Power and Distributive Politics: Federal Grants Expenditures In the 50 States, 1983-2001

Abstract: What explains the differences in federal spending in individual states across time? The current empirical literature on distributive politics has focused on Congress and neglected the presidency in explaining the distribution of federal spending, and it has looked at limited periods of time. I address these flaws by using Bayesian multilevel techniques to model of spending on grants over an extended period (1983-2001). Presidential variables are quite significant in influencing the distribution of grant expenditures.

Abstract: Analyses of federal spending across congressional districts have tended to ignore the institutional, geographical, and longitudinal context in which these districts are located. This neglects other sources of political influence, such as Senators, other representatives, party leaders, and Presidents. A decade-long data set (98th-102nd Congress, or 1983-1992) of defense procurement awards was collected and fitted to a Bayesian multilevel time series cross-sectional model. Partisan hypotheses from the modern literature on political determinants of federal spending are tested. There is little evidence that the Democratic party has been successful in steering defense spending towards Democrat districts, voters, members of the Armed Services committee, and Democratic state Congressional delegations–at a time period when Democrats were the Congressional majority and would have been expected to be able to do so.